For the construction of skeleton apartments a method is known for producing prefab wall panels of standard dimensions which are secured to each other on site. These panels generally consist of two parallel wooden boards which are secured to a frame (also called skeleton or framework) located between the two boards. To increase the insulation of the apartment, these wall panels are generally insulated on the site by making openings in the wooden boards and pouring a cellulose insulation into the openings. A drawback of this method is that it is highly labour intensive, that the openings in the boards have to be made in visible positions, and that a great deal of insulating material is wasted in most cases.
Alternatively the wall panels are pre-insulated in the factory with a soft insulation material such as glass wool or rock wool, or with hard insulation panels which have to be cut to size. However, a disadvantage of this method is that the wall panels are often poorly insulated and that there is a lot of cutting waste of the insulation material and that the method is labour intensive.
EP1683617A2 discloses a method for the automatic manufacture of panels, followed by a separate filling process in which a multiplicity of openings is made in both panels, the panels being inserted horizontally in a filling unit, and where pre-expanded filling material is inserted along openings in the uppermost panel in certain spaces between the panels, and where steam is then injected along openings in the bottom panel to bind the filling material. A disadvantage of this method is that it is highly labour intensive and susceptible to errors.